Cooking Properties of Akibare and Milyang 23 Brown Rice

아끼바레와 밀양23호 현미의 취반특성

Cooking rate calculated from hardness change, and gelatinization aspects observed by X-ray diffraction and scanning electron microscope of brown rice were investigated. Optimum ratio of water to rice of Akibare and Milyang 23 was 1.65 and 1.73, respectively. Milyang 23 was cooked at a faster rate than Akibare. Cooking rate of brown rice was about an half of white rice. The temperature dependence of cooking rate of brown rice was found to be relatively low. The activation energy for cooking were in the range of 15,000 to 16,400 cal/mol at 80 to $100^{\circ}C$ and 8,200 to 8,600 cal/mol at 100 to $130^{\circ}C$. The gelatinization degree determined from X-ray diffractometry was approximately consistent with the cooking degree expressed by reciprocal hardness.

아끼바레와 밀양 23호 현미의 취반에 있어서 취반중의 경도 변화에 의하여 취반 속도를 속도론적으로 분석하고 X-ray와 scanning electron microscope를 사용하여 호화양상을 비교하였다. 현미 취반의 최적 가수량은 아끼바레와 밀양 23호가 각각 1.65 및 1.73 배로써 다수확계가 다소 높은 최적 가수율을 보였다. 현미의 취반속도는 밀양 23호가 아끼바레보다 약간 빨랐으며, 백미보다는 약 2배 느렸다. 두 품종의 취반시 활성화에너지는 비슷하였으며 $80{\sim}100^{\circ}C$ 범위에서는 $15{\sim}16kcal/mol$, 100 - $130^{\circ}C$ 범위에서는 약 8. 5 kcal/mol이었다. 또한 X-ray 회절도로 호화도를 측정한 결과 연화도로 판정한 취반 종료점의 호화도는 거의 100%였다.